Blurring and pixelating images: how to do it safely

Updated: 2026-07-03 · 4 min read

Sharing a photo while hiding a child’s face, a license plate or an address on a document - that’s what pixelation and blur are for. Applied correctly, both are secure. But there are a few traps.

Pixelate or blur - which is safer?

Both methods replace the original pixels irreversibly: pixelation with coarse color blocks, blur with smoothing. What matters is the strength - a weak blur over a line of text can remain reconstructable.

Rule of thumb: for sensitive data (numbers, names, addresses), prefer pixelation at high strength so no character shapes remain recognizable. For faces, both work well.

The most common mistakes

Mistake 1: placing black bars as a layer over text in Office or PDF programs - those can often simply be removed, with the text underneath intact. Censoring must be baked into the pixels.

Mistake 2: hiding only the obvious. Reflections, screens in the background or documents on a desk also leak data. Scan the whole image once, calmly.

Mistake 3: forgetting metadata - photos can contain GPS coordinates. The BiGimg tool re-encodes the image, so such EXIF data does not survive.

Why the browser is the safest place for this

It sounds paradoxical: to anonymize an image, many people first upload it uncensored to a third-party server. That is exactly what to avoid with sensitive content.

The BiGimg censor tool works entirely locally in your browser - the uncensored original never leaves your device. Drag boxes, pick a strength, download, done.